1. IntroductionThe alleged chronic shortage of human organs has led
some researchers and federal health officials in the US
and elsewhere to consider using animals, such as pigs and
nonhuman primates, as alternate sources of organs for
humans. The prospect of commercial cross-species
transplantation (or xenotransplantation) - attempted
since the early 20th century - has created huge financial
incentives for biotechnology and pharmaceutical
companies. While some researchers and animal research
advocates are optimistic about xenotransplantation's
potential, others are calling for a moratorium on the
technology, which they say threatens public health and
the environment, has an appalling track record, and is
both expensive and unnecessary. These concerns have not
been satisfacto rily addressed by xenotransplantation's
proponents, who have overstated the technology's
potential benefits.

2.Organ Xenotransplantation's Track
Record: 100% FailureThere have been some 55 animal-to-human whole organ
transplants attempted since 1906. All have proven
unsuccessful, resulting in the suffering and death of all
patients and donor animals. The thousands of
cross-species experiments (between goats, rats and
chickens, rats and hamsters, cats and dogs, pigs and
primates) performed since 1906, and continuing today,
have not provided reliable information about what would
happen to human xenograft recipients. Xenotransplantation
is a dangerous and unproven technology.

3. Xenotransplantation Is
ExpensiveXenotransplantation is riskier and promises to be
even more expensive than human-to-human transplantation
($250,000 per operation in 1995, not including the hidden
costs of breeding, housing, feeding, medicating, testing,
transporting, rendering, and disposing of the waste and
remains of herds of transgenic animals). Institute of
Medicine figures from 1996 reveal that xenotransplant
costs for all patients who need organs could reach $20.3
billion. These costs are beyond the means of the majority
of Americans and an already overburdened health care
system. If ever successful, the technology would, at
best, benefit a small minority of patients (100,000)
while dramatically driving up health care costs for all.

4. We Should Learn From the
PastResponsible public health authorities would steer
clear of xenotransplantation in the interest of human
health, particularly in light of the knowledge that
animal viruses can jump the species barrier and kill
humans. HIV - the virus that causes AIDS - may be a
simian immunodeficiency virus (SIV) that leapt the
species barrier in central Africa. Health authorities
were unable to prevent the worldwide spread of HIV
infection. Similarly, they were unable to prevent Ebola
outbreaks in Sudan, Zaire (1976, 1979, 1995) and the US
(1989, 1996). Furthermore, there is evidence that humans
have become ill after consuming or being injected with
animal materials. There is a reported link between the
smallpox vaccine (derived from animal cells) and AIDS, a
recently acknowledged link between human lung, brain and
bone cancer and the SV (simian virus) 40 (found in old
batches of the Salk polio vaccine), and the threat of
emerging infectious diseases, including human
Creutzfeldt-Jakob Disease (CJD) from the consumption of
"mad cows" in Europe, the Netherlands, and the US.

5. Why Nonhuman Primates Should Not
Be Used As Organ "Donors"Baboon viruses flourish on human tissue cultures,
before killing the cultures. There are over 20 known,
potentially lethal viruses that can be transmitted from
nonhuman primates to humans, including Ebola, Marburg,
hepatitis A and B, herpes B, SV40, and SIV. Numerous
scientists have urged US public health agencies to
exclude primates as donors for xenotransplantation.

6. Why Pigs Should Not Be Used As
Organ "Donors"Given the acknowledged danger from nonhuman primate
viruses, pigs are being considered as the choice "donor"
animals for xenotransplants. However, pig retroviruses
have infected human kidney cells in vitro; and
virologists believe that many pig viruses have not been
adequately studied. Viruses that are harmless to their
animal hosts, can be deadly when transmitted to humans.
For example, Macaque herpes is harmless to Macaque
monkeys, but lethal to humans. The deadly human influenza
virus of 1918 that killed more than 20 million people
worldwide was a mutation of a swine flu virus that
evolved from American pigs and was spread around the
world by US troops. Leptospirosis (which produces liver
and kidney damage), and erysipelas (a skin infection),
are among the a pproximately 25 known diseases that can
be acquired from pigs, all of which could easily affect
immunosuppressed humans. There may be myriad unknown "pig
diseases" still to be discovered.In
addition, physiological and anatomical differences
between humans and pigs call into question the rationale
for their use. These include differences in life-span,
heart rate, blood pressure, metabolism, immunology, and
regulatory hormones. A pig heart put into a human will
turn black and stop beating in fifteen minutes. There is
no clinical evidence to suggest that this acute cellular
and vascular rejection will ever be overcome, or that
organs from genetically bred pigs are any less likely to
be rejected by the human body than those from
conventional pigs. Moreover, the massive doses of
immunosuppressive drugs that would be required for such
an operation would likely cause severe toxicity, and
increase the patient's chances of developing cancer.

8. No Way To Screen For Unknown
VirusesThere is no way to screen for unknown viruses.
Proceeding with xenotransplantation could expose patients
and non-patients to a host of new animal viruses which
could remain dormant for months or years before being
detected.Many
viruses, as innocuous as the common cold or as lethal as
Ebola, can be transmitted via a mere cough or sneeze. An
animal virus residing in a xenograft recipient might
become airborne, infecting scores of people, and causing
a potentially deadly viral epidemic of global proportions
akin to HIV or worse. It is highly unlikely that
scientists and health care workers would be prepared to
cope with such a scenario.

9. Unanswered Medico-Legal
QuestionsWould the US government be prepared to compensate
victims of xenogeneic infections (such as people who may
inadvertently contract an infection from a xenograft
recipient)? The French government was forced to establish
a $2.2 billion fund to compensate victims of
AIDS-contaminated blood transfusions administered between
1980 and 1985. Compensation claims in the US have been
filed by Persian Gulf War veterans, victims of secret
government-sanctioned radiation and syphilis experiments,
Vietnam war veterans exposed to Agent Orange, and parents
of vaccine-damaged children. The government may now also
be held liable for failing to protect citizens from
SV40-contaminated polio vaccine. And what about patients
who may choose to participate in privately-funded
research where there are no mechanisms of accountability
to federal health authorities, and little chance (for
patients and non-patients) of receiving remuneration for
injury or death. Can we afford another public health
catastrophe?

10. The Myth of the "Germ-Free"
AnimalXenotransplant proponents claim that they will breed
"germ-free" animals to diminish the risk of viral
transmission. But in its June 1996 report, the Institute
of Medicine acknowledged that "it is not possible to have
completely pathogen-free animals, even those derived by
Cesarean section, because some potentially infectious
agents are passed in the genome and others may be passed
transplacentally." Some British virologists say that it
would be "a daunting task to eliminate infectious
retroviruses from pigs to be used for
xenotransplantation, given that [they] estimate
approximately 50 PERV [pig endogenous
retroviruses] per pig genome."

11. Weak Regulatory Oversight, and
Human Error and Negligence, Would Facilitate Disease
TransmissionProposed regulatory oversight of xenotransplantation
procedures is weak and would likely be highly flawed.
Virologist Jonathan Allan has stated that, "in choosing
voluntary guidelines to be enforced at a local level
[via local institutional review boards], . . .
the FDA/CDC committee has chosen the least stringent and
possibly least successful method of policing these
transplant procedures.Moreover,
in all areas of human activity, particularly when money
is involved, the potential for fraud, error, and
negligence exists. In the past, such behavior has placed
human health at considerable risk. Witness the
HIV-contaminated blood scandals in France, China, Japan,
and the US, for example, in which employees and/or
medical authorities knowingly allowed HIV-contaminated
blood to be used for transfusions and blood-clotting
treatments for hemophiliacs.Given
the enormous amount of data, paperwork, and filing
xenotransplant procedures would generate, it would be
naive (given human nature) to assume that data will be
properly recorded, stored, reviewed, and updated.
Regulatory mechanisms often fail to prevent or correct
these errors and/or behaviors, the consequences of which
could be disastrous in the face of a xenogeneic
infection.

12. The Environmental Problems
Posed By XenotransplantationBreeding animals for xenotransplantation would create
a host of environmental problems (including soil and
groundwater contamination) associated with the disposal
of animal waste, and the carcasses of genetically
modified animals and their offspring. Conventional
farming and rendering operations have yet to solve these
problems which continue to threaten public health across
the US.

13. Eating Pigs Fuels Demand For
Pig OrgansIronically, it is precisely because people eat too
many pigs (and other factory-farmed animals), and have
unhealthy lifestyles, that pig organ transplants are
being considered. A large majority of heart, liver, and
kidney transplants could be prevented if people reduced
their meat, alcohol, and tobacco consumption. Federal
health authorities should be encouraging Americans to
take responsibility for their health by eating properly,
exercising, and avoiding cigarettes and alcohol.

14. We Should Be Investing In
Alternatives ToXenotransplantationBefore allocating US funds to such an extreme
technology as xenotransplantation, federal public health
agencies have a duty to explore proven, less costly, and
less risky alternatives. These include 1) preventive
health and health maintenance programs aimed at reducing
the need for transplants of all kinds, 2) administrative
programs to increase human organ donations, 3) clinical
research aimed at improving allotransplant technology,
and 4) technologies which lessen our dependence on
animals.Lifestyle
changes can reverse heart disease. Thirteen billion
dollars in medical costs could be saved and 100,000
first-time heart attacks averted by the year 2005 if
Americans simply reduced their average saturated fat
intake by 3 percentage points.Launching
government-funded education campaigns aimed at increasing
the pool of human organs should be considered. Neither
the government nor the medical community have
aggressively encouraged human organ donation. Currently,
only 20% of those individuals who die "healthy" have
arranged to donate their organs, even though 85% of the
public supports organ donation.Organ
availability quadrupled in Austria when its 'presumed
consent' law was enacted, and similar results prevail in
other European countries. The law assumes that everyone
is an organ donor unless they specify otherwise. If
presumed consent legislation were enacted in the US, 75%
of the adult US population (210,000,000) might become
committed potential organ donors. Another approach
involves creating a legal system of financial incentives
to increase organ donation.Finally,
we could be investing in surgical techniques to repair
malformed or poorly functioning organs. About 75% of
patients who undergo a procedure called ventricular
remodeling - in which a section of heart muscle is
removed and reshaped - can be taken off the transplant
waiting list.

15. ConclusionXenotransplantation places public health at
substantial risk and hence is an unacceptable technology.
Given our society's poor track record in managing the
consequences of modern science and technology, including
the increasing lethality of military weapons,
environmental pollution, rainforest destruction,
exponential population growth, and AIDS, we must honestly
ask ourselves whether we have the wisdom and moral
maturity needed to deal with the consequences of
xenotransplantation and related genetic technologies.
Until that question is publicly debated and, if ever,
answered, logic dictates a policy of restraint and
humility. In light of epidemiological, public health,
medical, scientific, economic, and environmental issues
surrounding xenotransplantation, the Medical Research
Modernization Committee advocates an indefinite freeze on
all forms of experimentation and clinical application of
the technology.

All points made in this essay are
documented in the full report, which is available from
the MRMC. Send check or money order in the amount of $5
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